Toothache can cause ear pain. This is a typical symptom of pulpitis, most of the pulpitis is due to the development of caries, caries is a kind of bacterial infection caused by dental hard tissue defects, dental tissue is divided into enamel, dentin, bone and pulp, of which the pulp is the so-called dental nerve, if the early stage of tooth decay is not treated in time, the bacteria further infect the dental nerve will appear the symptoms of pulpitis. The most typical symptoms of pulpitis are night pain and pain that cannot be localized. Inflammation of the nerve of a tooth can cause pain in the upper and lower teeth on the same side, and it is impossible to pinpoint which tooth is in pain. This kind of ear pain caused by toothache needs to be distinguished from trigeminal neuralgia, and sometimes it can be mistaken for otitis media, so careful diagnosis is needed.